| 摘要 |
A composite antenna system for an article surveillance system, in which a plurality of differentlyphased loop antennas are supplied with different currents to provide desired positioning of peaks and nulls in the nearfield strength, and to produce near-zero far-field strength, as desired. In one preferred form, a smaller loop is placed near the floor and a larger loop placed above it, with the lower loop supplied with a correspondingly higher-intensity of current to provide an enhanced near-field strength near the floor, while still maintaining far-field cancellation.
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